1. Field of the Invention
The present invention relates to a rotary electric machine that is used in an automotive electric motor, etc., that is mounted to an automobile, for example, and particularly relates to an insulating construction for a concentrated winding that is wound edgewise onto teeth of a stator.
2. Description of the Related Art
Conventional stators in which concentrated windings are applied to pole tooth portions of a stator core include insulating sheets that axially cover concave slot portions that are formed on two sides of the pole tooth portions, and straight portions and coil end portions of winding bodies are insulated by the insulating sheets (see Patent Literature 1, for example).
Patent Literature 1: Japanese Patent Laid-Open No. 2003-61286 (Gazette)
In conventional stators, the straight portions and the coil end portions of the winding bodies are covered and insulated by the insulating sheets, but no mention is made of insulating leader lines that are led out from winding start end portions and winding finish end portions of the winding bodies.
In winding bodies that are wound into concentrated windings on the pole tooth portions, because the electric potential difference between the winding start end portions and the winding finish end portions of the winding bodies is increased, it is necessary to ensure sufficient insulating distance between the leader lines that are led out from the winding start end portions and the winding finish end portions of the winding bodies. If a conductor wire that has a circular cross section is wound onto a pole tooth portion in multiple rows in multiple layers from radially outside, for example, the leader line at the winding start is led radially outward from the radially outermost position of the innermost layer of the winding body (the winding start end portion), and the leader line at the winding finish is led radially outward over a coil end portion from the radially innermost position of the outermost layer of the winding body (the winding finish end portion). Thus, an insulating distance that corresponds to the layer thickness of the coil end portion is ensured between the two leader lines.
However, if a conductor wire that has a rectangular cross section is wound onto a pole tooth portion in multiple rows in a single layer in an edgewise winding, the leader line at the winding start is led out from the radially outermost position of the winding body (the winding start end portion), and the leader line at the winding finish is led radially outward over a coil end portion from the radially innermost position of the winding body (the winding finish end portion). The insulating distance between the two leader lines is then a distance between the leader line at the winding finish and a row that is positioned at the outermost radius of the winding body. Thus, in order to ensure sufficient insulating distance between the two leader lines, it is necessary to increase the distance between the leader line that is led out from the winding finish end portion and the coil end portion, and one problem has been that axial length of the stator is increased, and reductions in size cannot be achieved.